http://sourceware.org/ml/gdb-patches/2012-11/msg00312.html

gdb/ChangeLog
        * valarith.c (value_vector_widen): New function for replicating a
        scalar into a vector.
        (value_binop): Use value_vector_widen to widen scalar to vector
        rather than casting, this better matches gcc C behaviour.
        * valops.c (value_casst): Update logic for casting between vector
        types, and for casting from scalar to vector, try to match gcc C
        behaviour.
        * value.h (value_vector_widen): Declare.
        * opencl-lang.c (opencl_value_cast): New opencl specific casting
        function, handle special case for casting scalar to vector.
        (opencl_relop): Use opencl_value_cast.
        (evaluate_subexp_opencl): Use opencl_value_cast instead of
        value_cast, and handle BINOP_ASSIGN, UNOP_CAST, and UNOP_CAST_TYPE
        in order to use opencl_value_cast.

gdb/testsuite/ChangeLog
        * gdb.base/gnu_vector.c: New variable for use in tests.
        * gdb.base/gnu_vector.exp: Update and extend tests to reflect
        changes in scalar to vector casting and widening.
        * gdb.python/py-type.c: New variables for use in tests.
        * gdb.python/py-type.exp: Update vector related tests to reflect
        changes in scalar to vector casting and widening.

1 files changed, 7 insertions, 23 deletions

diff --git a/gdb/valops.c b/gdb/valops.c
index e3d36a1..b9bc460 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -546,29 +546,13 @@ value_cast (struct type *type, struct value *arg2)
 	 minus one, instead of biasing the normal case.  */
       return value_from_longest (type, -1);
     }
-  else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar)
-    {
-      /* Widen the scalar to a vector.  */
-      struct type *eltype;
-      struct value *val;
-      LONGEST low_bound, high_bound;
-      int i;
-
-      if (!get_array_bounds (type, &low_bound, &high_bound))
-	error (_("Could not determine the vector bounds"));
-
-      eltype = check_typedef (TYPE_TARGET_TYPE (type));
-      arg2 = value_cast (eltype, arg2);
-      val = allocate_value (type);
-
-      for (i = 0; i < high_bound - low_bound + 1; i++)
-	{
-	  /* Duplicate the contents of arg2 into the destination vector.  */
-	  memcpy (value_contents_writeable (val) + (i * TYPE_LENGTH (eltype)),
-		  value_contents_all (arg2), TYPE_LENGTH (eltype));
-	}
-      return val;
-    }
+  else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type)
+	   && code2 == TYPE_CODE_ARRAY && TYPE_VECTOR (type2)
+	   && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
+    error (_("Cannot convert between vector values of different sizes"));
+  else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar
+	   && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
+    error (_("can only cast scalar to vector of same size"));
   else if (code1 == TYPE_CODE_VOID)
     {
       return value_zero (type, not_lval);